<!doctype HTML>
<html>
<meta charset="utf8">
<title>Content Visibility: off-screen selection</title>
<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
<meta name="assert" content="content-visibility auto element remains non-skipped when elements in its subtree have selection.">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<style>
body, html {
  padding: 0;
  margin: 0;
}

.spacer {
  height: 3000px;
  background: lightblue;
}
#container {
  background: lightgreen;
  contain-intrinsic-size: 50px 100px;
  content-visibility: auto;
}
#selectable {
  width: 10px;
  height: 10px;
}
</style>

<div class=spacer></div>
<div id=container>
  <div id=selectable>hello</div>
</div>
<div class=spacer></div>

<script>
async_test((t) => {
  const selection = window.getSelection();
  const range = document.createRange();
  range.selectNodeContents(selectable);

  // Initially container should be 3000px offscreen with contained height 100px.
  function step1() {
    const r = container.getBoundingClientRect();
    t.step(() => {
      assert_equals(r.y, 3000, "step1 offset");
      assert_equals(r.height, 100, "step1 height");
    });

    selection.removeAllRanges();
    selection.addRange(range);

    requestAnimationFrame(step2);
  }
  // The container has a selection so it should be smaller now, height 10px.
  function step2() {
    const r = container.getBoundingClientRect();
    t.step(() => {
      assert_equals(r.y, 3000, "step3 offset");
      assert_equals(r.height, 10, "step3 height");
    });
    document.scrollingElement.scrollTop = 3000;
    requestAnimationFrame(step3);
  }
  // After scrolling the container should be closer and still height 10px.
  function step3() {
    const r = container.getBoundingClientRect();
    t.step(() => {
      assert_less_than(r.y, 3000, "step2 offset");
      assert_equals(r.height, 10, "step2 height");
    });
    document.scrollingElement.scrollTop = 0;
    requestAnimationFrame(step4);
  }
  // Scrolling back to the top we should remain at height 10px.
  function step4() {
    const r = container.getBoundingClientRect();
    t.step(() => {
      assert_equals(r.y, 3000, "step4 offset");
      assert_equals(r.height, 10, "step4 height");
    });
    requestAnimationFrame(step5);
  }
  // Repeat step4 to ensure we're in a stable situation.
  function step5() {
    const r = container.getBoundingClientRect();
    t.step(() => {
      assert_equals(r.y, 3000, "step4 offset");
      assert_equals(r.height, 10, "step4 height");
    });

    selection.removeAllRanges();

    requestAnimationFrame(step6);
  }
  // After removing the selection we should go back to the contained
  // height of 100px.
  function step6() {
    const r = container.getBoundingClientRect();
    t.step(() => {
      assert_equals(r.y, 3000, "step5 offset");
      assert_equals(r.height, 100, "step5 height");
    });
    t.done();
  }
  step1();
});
</script>
</html>
